Drill-pipe buffer



July 25, 1939. w l, BETTIS 2,166,937

DRILL-PIPE BUFFER Filed F'eb. 4, 1938 Homey.

UNITED STATES PATENT OFFICE DRILL-PIPE BUFFER William I. Bettis, Los Angeles, Calif., assigner to Estelle B. Kleaver, Burbank, Calif.

Application February 4, 1938, Serial No. 188,682

8 Claims. (Cl. Z55-28) My invention relates to drill-pipe buiers, and particularly to types thereof which are adapted for use in deep well drilling operations below the well casings. Among the more important objects att i6: and drill pipe within the well is indicated a.

The present invention, in the embodiment selected for this disclosure, comprises a cylindrical of the invention are; rst, to further advance the annulus 8 of resilient material, such as suitably 5 art of obtaining straight drill holes; second, to compounded vulcanized rubber. The characterfurnish means for preventing injury to the walls istics and dimensions of this annulus are such that of uncased drill holes as the result of vibrations it can be stretched around the drill pipe with in suspended drill strings; third, to furnish pracwhich it is to be used, as shown in Figs. 1 and 2; tical mechanical means for mud-plastering unand such that, when so positioned, it will grip l0 cased drill hole walls; fourth, to supply further the pipe very tightly, and be practically immovimproved means for reducing the over-al1 ilow able thereon under service stresses. The unresistance of circulating uid in deep well drillstretched annulus is shown in Fig. 3, and it will ing; and, ifth, to accomplish all the stated obbe noted that the diameter of its bore 9 is matejects concurrenty, by means of a simple and relarially less than the outside diameter of drill l5 tively inexpensive device. pipe l.

My objects are attained in the manner illus- Around the periphery of the annulus are a trated in the accompanying drawing, in whichnumber 0f impeller-Shaped, and quasi-helical, Figure l is a central sectional elevation of a varies ll. I'he dimensions and shapes of these deep well, at and just below the well casing; do not change materially by stretching the annu- 20 showing, in elevation, a. portion of a drill pipe 111s, eXCept possibly as t0 longitudinal pitch. therein, and my improved buffer mounted upon When the device is stretched upon a drill pipe and the drill pipe; used in a deep well, for which it is adapted in Figure 2 is a cross-section of the well and drill both cases; the outer diameter of the device, over pipe, taken on the plane 2 2 of Fig. 1; and the vanes, will be such as to t the bore of the 25 Figure 3 is a plan view oi the particular buffer Well With Smell Clearance. eS ShOWn at I2. The shown in Figs, 1 and 2, before it is applied to a resistance of valles Il t0 radially inward medriu pipe, chanical stresses, is made such that the drill pipe Similar reference numerals refer to similar may be kept Closely Centered in the Well at all things throughout the several views. times by this means. The vanes. however, by rea- 3o It will be appreciated that, in view of this dis- SOn 0f their resilient nature. dne t0 Shaping and closure, my invention may assume a number of material used. Can yield somewhat under radial specific forms. Consequently I do not limit my Stress; and thus the centering function 0f the claims to the particular embodiment herein venes may be utilized either in cased 0r uncased Shown and described, drill holes. 'I'he maximum straightness of drill- 35 In two presently pending applications for U. S. ing, With Present knowledge in the art. is obtainpatents (Ser. No. 178,297 and Ser. No. 178,298), able in this manner. The slight clearance bel discussed the desirability of utilizing cased bores tween the venes and the Walls 0f the Well, either of deep wells as guides for keeping drill pipes cencased or uncased, prevents Objectionable vibratered therein; for the dual purposes of securing tion of the drill pipe. 40 straighter drill holes, and reducing damaging A utility of my invention, which hitherto has vibrations in suspended drill pipes. The present been unattainable, is the mechanical mud-plasterinvention extends such art by making it possible ing oi the walls of uncased drill holes which it is to utilize the uncased bore of the well in a simiadapted to perform. 'I'his is particularly desirlar manner. A able when drilling in open formations; and it is Neither U. S. Patent No. 1,573,031, issued to accomplished by the troweling action of impeller- Leroy H. Perry and myself jointly; nor U. S. Patshaped vanes Il, when the device is revolved in ent No. 1,863,740 issued to me alone; disclose dethe direction of arrow 5. The plastering material, vices which can function, in certain respects, in of course, normally consists ofA the heavy mud the manner of the invention described and shown present in the circulating duid; but the device is herein, perfectly capable of utilizing other plastering In the accompanying drawing, it is assumed material, introduced into the well through the that the drilling rotation will be clockwise when bore of the drill string or otherwise. When thus looking downwardly, as indicated by arrow 5. A plastered, the uncased wall of the well will be section of the lower end of a well casing is shown both smooth and tight; and it will remain tight,

since the internal hydraulic pressure always is, or may be made to be, greater than that in the surrounding ground.

The quasi-helical shape of vanes il enables them to impart a strong upward flow impulse to the circulating fluid; and their spacing provides upward iiow passages therefor.

In the drawing, an embodiment having six impeiling vanes is shown. Leading surfaces of these vsnl? are indicated at I3, and a trailing surface at It will be obvious that any desired entrance and discharging angles may be given to vanes Il for impelling purposes; and that the rearward curvature,` to provide the troweling action, may be.

made as appears to be most desirable. The device may be positioned upon a drill pipe by means other than gripping as the result of resilient stretching, in many ways that are known in the drilling and other mechanical arts. It will also be apparent that material `other than rubber maybe utilized for the device, when and as material `which is suitable for the purpose is developed and becomes commercially available.

Finally): callattention to the fact, that the rearward curvature of vanes Il strongly tends to center the device in service, by means of the radially outward pressures they exert upon the iiuid in the well.

Having thus fully disclosed my invention, I claim:

1. A device of the character described, comprising; an annulus adapted for mounting upon a. co-axial drill pipe, and having quasi-helical vanes extending outwardly from its periphery; said vanes being curved rearwardly with respect to the intended direction of rotation when the device is so mounted, and being adapted to impel circulating iluld upwardly when the device is rotated within a co-axial cylindrical bore which it iits with small clearance.`

2. A device of the character described, comprising; an annulus adapted for mounting upon a co-axiai drill pipe, and having quasi-helical vanes extending outwardly from its periphery; said vanes being curved rearwardly with respect to the intended direction of rotation when the device is so mounted; and, when the device is rotated within a co-axial cylindrical bore which it ilts with small clearance, the vanes being adapted to impel circulating iluid upwardly, and also to exert a troweling eiiect upon the surrounding wall.

3. A device of the character described, comprising; a cylindrical annulus adapted for mounting upon a co-axial drill pipe, and having resilient quasi-helical vanes extending outwardly from its cylindrical periphery and rearwardly with respect to the intended direction of rotation when the device is so mounted.

4. A device of the character described, comprislng; a cylindrical annulus adapted `for mounting upon a coaxial drill pipe, and having quasihelical vanes extending outwardly from its cylindrical periphery and rearwardly with respect to the intended direction of rotation when the device is so mounted; said vanes being resilient and adapted to serve as a buffer between the drill pipe and the wall of a co-axial cylindrical bore which the device ts with small clearance.

5. A device of the character described, cornprising; an annulus of resilient material, adapted for being stretched around a drill pipe to grip it; the annulus having quasi-helical resilient vanes extending outwardly from its circular periphery; and said vanes being directed rearwardly with respect to the intended direction of rotation when the device is so mounted.

6. A device of the character described, cornprising; a cylindrical annulus of resilient material, adapted for being stretched around a drill pipe to grip it; the annulus having quasi-helical resilient vanes, extending outwardly from its cylindrical periphery, and rearwardly with respect to the intended direction of rotationv when the device is so mounted; and the vanes being adapted to serve as impellers for circulating fluid when the device is rotated in a cylindrical bore which it fits with small clearance.

7. A device of the character described, comprising; a cylindrical annulus of resilient material, adapted for being stretched around a drill pipe to grip it; the annulus having quasi-helical vanes, extending outwardly from its cylindrical periphery, and rearwardly with respect to the intended direction of rotation when the device is so mounted; and the vanes being adapted to exert a troweling eilect upon the wall of a co-axial cylindrical bore which the device ts with small Clearance. 

